The present invention relates to a lagging body for a belt conveyor pulley.
In a conventional belt conveyor device, a rubber lining has been widely used on the outer periphery of the belt contacting surface of the drive pulley. However, such a pulley is quickly worn out. Further, as a snap pulley or the like, a metal drum having no lining is often used, but such a metal drum is easily worn out and is also swollen when the conveyed material becomes adhered to its outer periphery. As a result, the belt is disturbed from its normal driving and meanders like a snake and has to be stopped occasionally. Some snap pulleys are lined with rubber plates, but such pulleys are severely worn out and have to be exchanged every 2-3 months.
It has been known to secure ceramic lagging elements on the outer surface of metallic pulley for a belt conveyor in order to increase the friction coefficient. However, the pulley having ceramic lagging elements adhered on the surface is generally completed as a final product in a factory and transported to the place where the pulley is required. Therefore, if an old type pulley only lined with rubber plate has to be exchanged for a new type pulley which has ceramic lagging elements on the surface thereof, it takes a long time to wait for the arrival of a new type pulley and it requires a lot of expenses.
Recently, there has been proposed a pulley in which the cylindrical periphery of the pulley drum is adhered with a lagging element comprising of wear-resistant ceramics. Such lagging element is used for drive pulley and produced by adding a proper amount of synthetic resin bonding agent to a desired amount of ceramic particles such as alumina having a comparatively large grain size, and molding and sintering so as to have a coarse surface. These heretofore proposed lagging elements are produced by mixing phenol resin or polyurethane as a bonding agent into ceramic particles and molding and heating at low temperature. However, because the bonding agent is easily aged or deteriorated, such lagging element has drawbacks that its weather resistant and water resisting properties are poor and the ceramic particles are liable to be removed, and its durability is unreliable.